package workbench

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"
)

// fakeOllama 模拟 Ollama 的 /api/embed 与 /api/pull。dim 固定产出向量维数,
// requireModel 为 true 时首次 /api/embed 返回 404 触发 /api/pull。
func fakeOllama(t *testing.T, dim int, requireModel bool) *httptest.Server {
	t.Helper()
	pulled := false
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/api/pull":
			pulled = true
			_ = json.NewEncoder(w).Encode(map[string]any{"status": "success"})
		case "/api/embed":
			if requireModel && !pulled {
				w.WriteHeader(http.StatusNotFound)
				_ = json.NewEncoder(w).Encode(map[string]any{"error": "model 'bge-m3' not found"})
				return
			}
			var body struct {
				Input []string `json:"input"`
			}
			_ = json.NewDecoder(r.Body).Decode(&body)
			embeddings := make([][]float32, len(body.Input))
			for i := range body.Input {
				vector := make([]float32, dim)
				for j := range vector {
					vector[j] = float32(i + 1)
				}
				embeddings[i] = vector
			}
			_ = json.NewEncoder(w).Encode(map[string]any{"embeddings": embeddings})
		default:
			http.NotFound(w, r)
		}
	}))
	t.Cleanup(server.Close)
	return server
}

func TestOllamaEmbedderBatching(t *testing.T) {
	server := fakeOllama(t, 4, false)
	embedder := NewOllamaEmbedder(OllamaEmbedderConfig{BaseURL: server.URL, Model: "bge-m3", Dim: 4, BatchSize: 2, Timeout: 5 * time.Second})
	texts := []string{"a", "b", "c", "d", "e"}
	vectors, err := embedder.Embed(context.Background(), texts)
	if err != nil {
		t.Fatal(err)
	}
	if len(vectors) != len(texts) {
		t.Fatalf("got %d vectors want %d", len(vectors), len(texts))
	}
	for i, vector := range vectors {
		if len(vector) != 4 {
			t.Fatalf("vector %d has dim %d want 4", i, len(vector))
		}
	}
	if embedder.Dim() != 4 {
		t.Fatalf("Dim()=%d want 4", embedder.Dim())
	}
}

func TestOllamaEmbedderDimensionMismatch(t *testing.T) {
	server := fakeOllama(t, 3, false)
	embedder := NewOllamaEmbedder(OllamaEmbedderConfig{BaseURL: server.URL, Model: "bge-m3", Dim: 4, BatchSize: 2, Timeout: 5 * time.Second})
	_, err := embedder.Embed(context.Background(), []string{"x"})
	if err == nil || !strings.Contains(err.Error(), "dimension mismatch") {
		t.Fatalf("expected dimension mismatch error, got %v", err)
	}
}

func TestOllamaEmbedderPullsModelOn404(t *testing.T) {
	server := fakeOllama(t, 4, true)
	embedder := NewOllamaEmbedder(OllamaEmbedderConfig{BaseURL: server.URL, Model: "bge-m3", Dim: 4, BatchSize: 8, Timeout: 5 * time.Second})
	vectors, err := embedder.Embed(context.Background(), []string{"hello", "world"})
	if err != nil {
		t.Fatalf("expected pull-then-retry to succeed, got %v", err)
	}
	if len(vectors) != 2 {
		t.Fatalf("got %d vectors want 2", len(vectors))
	}
}

func TestOllamaEmbedderEmptyInput(t *testing.T) {
	embedder := NewOllamaEmbedder(OllamaEmbedderConfig{BaseURL: "http://127.0.0.1:1", Model: "bge-m3", Dim: 4, BatchSize: 2, Timeout: time.Second})
	vectors, err := embedder.Embed(context.Background(), nil)
	if err != nil || len(vectors) != 0 {
		t.Fatalf("empty input should return nil without HTTP: vectors=%d err=%v", len(vectors), err)
	}
}

func TestFormatVector(t *testing.T) {
	if got := formatVector([]float32{1, 2.5, -0.25}); got != "[1,2.5,-0.25]" {
		t.Fatalf("formatVector got %q", got)
	}
	if got := formatVector([]float32{}); got != "[]" {
		t.Fatalf("formatVector empty got %q", got)
	}
}